Dinoprostone

Extra-amniotic
Pregnancy termination in the 2nd trimester
Adult: Instill 1 mL via suitable foley catheter followed by 1-2 mL at 2 hr intervals according to patient's response.
Reconstitution: Dilute w/ 50 mL of the diluent provided to prepare a soln containing 100 mcg/mL.

Intravenous
Pregnancy termination in the 2nd trimester
Adult: 2.5 mcg/min via infusion over 30 min, then maintain or increase to 5 mcg/min. Maintain for at least 4 hr before increasing further.
Reconstitution: Dilute w/ appropriate volume of NaCl 0.9% or dextrose 5% to prepare a soln containing 5 mcg/mL.

Endocervical
Cervical priming, induction and augmentation of labour
Adult: As cervical gel: Insert 0.5 mg into the cervical canal, may be repeated at 6 hr interval, if needed. Max: 1.5 mg/24 hr.

Vaginal
Cervical priming, induction and augmentation of labour
Adult: As vag device or insert delivering 0.3 mg/hr: Administer 1 vag device/insert (10 mg) high into posterior fornix and remove when cervical ripening is complete, or after 12-24 hr (depending on product) if cervical ripening is insufficient.

Vaginal
Labour induction
Adult: As vag gel: 1 mg (or 2 mg in primigravid patient w/ unfavourable induction features) inserted into the posterior fornix, followed by 1-2 mg after 6 hr, if needed. Max: 3 mg (or 4 mg in unfavourable primigravid patient) per course. As vag tab: 3 mg inserted high into the posterior fornix, followed by a further 3 mg after 6-8 hr, if necessary. Max: 6 mg per course.

Vaginal
Pregnancy termination in the 2nd trimester
Adult: As vag supp: Insert 1 supp (20 mg) high into the posterior fornix, repeat at 3-5 hr interval until abortion occurs, for up to 2 days.

Acute or history of pelvic inflammatory disease, vag infections or cervicitis, placenta praevia or unexplained vag bleeding, history of major uterine surgery or caesarean section, cephalopelvic disproportion, foetal malpresentation, foetal distress, grand multiparae, history of traumatic delivery, ruptured membranes. Active cardiac, pulmonary, renal or hepatic disease.

Patient w/ compromised uteri, asthma, glaucoma, raised intraocular pressure, HTN or CV disease, epilepsy, gestational diabetes, hypothyroidism. Compromised cardiac, hepatic, or renal function. Monitoring Parameters Monitor foetal heart rate, uterine activity, progression of cervical dilation and effacement (gel, insert); confirmation of foetal death (supp).

Significant: Rarely, disseminated intravascular coagulation (DIC). CV: HTN. GI: Diarrhoea, nausea, vomiting. Resp: Asthma, bronchospasm. Genitourinary: Uterine hypertonus, uterine rupture, abruptio placenta, pulmonary amniotic fluid embolism, rapid cervical dilatation, vag warmth, irritation, and pain. Musculoskeletal: Back pain. Dermatologic: Rash. Immunologic: Anaphylactoid reactions including shock. Others: Fever.
Potentially Fatal: Cardiac arrest.

Symptoms: Uterine hypercontractility, uterine hypertonus. Management: Conservative treatment (including change in maternal position or admin of oxygen); if not effective, β-adrenergic agents may be given.

Potentiates the uterotonic effect of oxytocic drugs.

Dinoprostone, a prostaglandin E₂, stimulates uterine smooth muscle, thereby inducing uterine contractions similar to those produced by the body during spontaneous labour. It also promotes cervical ripening through activation of the collagenase enzyme which is responsible for digestion of some of the structural collagen network in the cervix. This results in cervical smooth muscle relaxation, allowing dilation and passage of the foetus through the birth canal.
Onset: W/in 10 min (vag supp).
Duration: 2-3 hr (vag supp); 0.3 mg/hr over 12 hr (vag insert).
Absorption: Slowly absorbed (vag supp). Time to peak plasma concentration: 30-45 min (cervical gel).
Distribution: Rapidly distributed (IV). Diffuses into the maternal blood. Enters breast milk.
Metabolism: Extensively metabolised in the lungs, forming metabolites which are further metabolised in the liver and kidney.
Excretion: Mainly via urine; faeces (small amounts). Elimination half-life: 2.5-5 min.

Endocervical: Store between 2-8°C. Extra-amniotic: Store at 4°C. Intravenous: Store at 4°C. Vaginal: Store below -20°C.

Drugs Acting on the Uterus

G02AD02 - dinoprostone ; Belongs to the class of prostaglandins. Used to induce abortion or augment labour and to minimize blood loss from the placental site.